JPH10206703A - Optical fiber ribbon and optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber ribbon having high mechanical strength and ease of peeling, and to provide an optical fiber cable having a lowermost layer when laminated to form an optical fiber cable. To provide an optical fiber cable free from increase in transmission loss. SOLUTION: A plurality of optical fiber core wires are aligned to UV.
In an optical fiber ribbon coated with a curable resin, both sides of the optical fiber ribbon coated with the first and second UV-curable resins having different Young's moduli are separated by a plane formed by aligning the optical fibers. The optical fiber ribbon and the optical fiber ribbon 1 are stacked and housed in the groove so that the side coated with the higher Young's modulus UV-curable resin faces the bottom surface of the slot rod groove. Fiber optic cable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber ribbon obtained by aligning a plurality of optical fibers and coating with a UV curable resin, and laminating the optical fiber tape in a groove of a slot rod. The present invention relates to an optical fiber cable housed and stored.

[0002]

2. Description of the Related Art As shown in FIG. 3, an optical fiber ribbon constituting an optical fiber cable used in an optical communication system is composed of an optical fiber 100 made of glass or plastic and a primary fiber made of a UV-curable resin. Layer 10
1 and a secondary layer 102, and further a colored layer 1
In general, a plurality of (four in the example in the figure) optical fiber cores coated with 03 are arranged and further collectively covered with a UV-curable resin 104. Then, a predetermined number of the optical fiber tape cores are stacked and stored in a slot rod groove (not shown), and the outer periphery thereof is sequentially wound with a holding tape or a cable sheath (not shown). Optical fiber cable.

In such an optical fiber cable,
The transmission loss of the lowermost optical fiber ribbon in contact with the groove bottom of the slot rod may increase due to lateral pressure, friction, and the like between the bottom and the groove bottom. In addition, in recent years, there has been a high demand for so-called high-density optical fiber tape cores to be accommodated by increasing the number of optical fiber tape cores accommodated per slot of a slot rod in order to increase the transmission amount of optical fiber cables. The coating thickness of the UV curing resin 104 tends to be thin, and the transmission loss of the lowermost optical fiber ribbon as described above tends to increase. As a technique for solving such a problem, Japanese Patent Application Laid-Open No. 2-47613 discloses an optical fiber ribbon coated with a UV-curable resin having a higher Young's modulus than before. This optical fiber ribbon is coated with a high Young's modulus, that is, a UV-curable resin with high hardness, so that the mechanical strength is increased, and the resistance to lateral pressure between the slot rod groove bottom and friction is improved. I do.

[0004]

However, when connecting or branching optical fiber cables, this kind of optical fiber ribbon may be separated into individual optical fiber ribbons by peeling the UV curable resin. This peeling work is extremely difficult when coated with a UV-curable resin having a high Young's modulus, such as the optical fiber ribbon described in JP-A-2-47613.

The present invention has been made in view of the above circumstances, and provides an optical fiber ribbon having both high mechanical strength and ease of peeling, and an optical fiber ribbon when laminated to form an optical fiber cable. It is an object of the present invention to provide an optical fiber cable which does not increase the transmission loss of the lowermost optical fiber tape.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical fiber ribbon, in which a plurality of optical fibers are aligned and coated with a UV-curable resin. An optical fiber ribbon, characterized in that both sides thereof are coated with first and second UV-curable resins having different Young's moduli from a plane formed by aligning, and the optical fiber ribbon, This is achieved by an optical fiber cable in which the side covered with the UV-curable resin having the higher Young's modulus is laminated and housed in the groove so as to face the bottom surface of the groove of the slot rod.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical fiber ribbon and an optical fiber cable according to the present invention will be described below with reference to the drawings. First, the optical fiber ribbon will be described. As shown in FIG. 1 as a cross-sectional view, an optical fiber ribbon 1 of the present invention covers an optical fiber 10 made of glass or plastic with a primary layer 11 and a secondary layer 12 made of a UV-curable resin. A plurality (four in the example in the figure) of optical fiber cores covered with the colored layer 13 are arranged, and both sides (upper and lower parts in the figure) of a plane formed by aligning the optical fiber cores are bordered. Are coated with first and second UV-curable resins having different Young's moduli.

Here, the Young's modulus of the first UV-curable resin may be larger than the Young's modulus of the second UV-curable resin. The smaller one is denoted by reference numeral 14 as the upper layer, while the reference numeral 15 is denoted as the second UV-curable resin as the lower layer. Further, the value of the Young's modulus of the first UV-curable resin 14 and the value of the Young's modulus of the second UV-curable resin 15 can be set appropriately relative to each other. Considering the case of lamination, the first U
The Young's modulus of the V-curable resin 14 is 80 to 90 (kg / mm).
² , 23 ° C.), and the Young's modulus of the second UV-curable resin 15 is preferably 110 to 130 (kg / mm ² , 23 ° C.). Incidentally, these UV-curable resins are not particularly limited in the type, composition, molecular weight and the like of the resin as long as they satisfy the above range of Young's modulus.
Further, it can be adjusted to the above range of Young's modulus according to a standard method, or can be obtained from the market. Further, the UV-curable resin is transparent when cured, but in the present invention,
For example, it is preferable to color the resin having the higher Young's modulus so that the resin can be identified. This coloring can be performed, for example, by mixing an appropriate pigment into the resin or by applying a paint after forming the optical fiber ribbon.

As described above, in the optical fiber ribbon 1 of the present invention, the upper half of the optical fiber ribbon is made of the first UV-curable resin 14 having a low Young's modulus, and the lower half is made of the first UV-curable resin 14 having a high Young's modulus. It is covered with a UV-curable resin 15 and molded into a tape shape as a whole. Therefore, since there is a difference in the Young's modulus between the UV curing resins constituting the upper and lower layers,
Peeling is easy at the boundary B, and there is no hindrance to the peeling work even though it has a high Young's modulus portion having excellent mechanical strength.

Incidentally, the optical fiber ribbon 1 of the present invention comprises:
For example, a predetermined number of optical fibers are continuously conveyed in an aligned state, and the first and second UV-curable resins are simultaneously applied on both sides of the aligned surface as a boundary, and the whole is irradiated with ultraviolet rays. It can be produced by curing.

The difference in the Young's modulus between the UV-curable resins constituting the upper and lower layers is also advantageous when a large number of optical fiber ribbons are laminated when an optical fiber cable is used. FIG. 2 is a cross-sectional view of a main part of the optical fiber cable of the present invention. As shown, a plurality of the optical fiber ribbons 1 are made of a second UV-curable resin having a high Young's modulus. 15 is the slot rod 2
The optical fiber cable is housed in the groove 21 in a state of being stacked so as to face the bottom surface 22 of the groove 21 of the groove No. 0. Becomes

In such a laminated state, each optical fiber ribbon 1 is mounted on the surface of the other optical fiber ribbon 1 made of the first UV-curable resin 14. Since the first UV-curable resin 14 has a low Young's modulus and is soft, it functions as a cushioning material and absorbs a side pressure (stress) applied to each optical fiber ribbon 1 to reduce the transmission loss characteristics. Can be prevented. Each of the optical fiber ribbons 1 has a hard second U having a high Young's modulus in the lower layer.
Since it is formed of the V-curable resin 15, even when the lowermost layer is formed, it is possible to suppress an increase in transmission loss due to lateral pressure, friction and the like with the slot bottom surface 22 of the slot rod 20.

Although the optical fiber cable of the present invention may be formed by laminating a predetermined number of the optical fiber ribbons 1 shown in FIG. 1, the lowermost optical fiber ribbon which is in contact with the groove bottom surface 22 of the slot rod 20 is provided. Only the optical fiber ribbon 1 shown in FIG. 1 can be used, and a conventional optical fiber ribbon can be laminated thereon.

[0014]

As described above, the optical fiber ribbon of the present invention has a structure in which the upper and lower portions of the optical fiber are covered with the first and second UV curable resins having different Young's moduli. Therefore, peeling is easy at the boundary between the two resins, and the peeling operation can be easily performed while having a high Young's modulus portion having excellent mechanical strength. Further, the optical fiber cable of the present invention is laminated so that the side coated with the second UV-curable resin having a high Young's modulus of the above-mentioned optical fiber ribbon is opposed to the groove bottom surface of the slot rod. Each optical fiber ribbon is placed on a soft resin having a low Young's modulus, and the side pressure applied to each optical fiber ribbon is reduced. In addition, the lowermost layer of the optical fiber ribbon also has a high Young's modulus at the portion that rubs against the groove bottom surface of the slot rod, which is a hard second UV-curable resin, so that an increase in transmission loss can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an optical fiber ribbon according to the present invention.

FIG. 2 is a cross-sectional view of a main part showing one embodiment of the optical fiber cable of the present invention.

FIG. 3 is a cross-sectional view showing a conventional optical fiber ribbon.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber tape core wire 10 Optical fiber strand 11 Primary layer 12 Secondary layer 13 Colored layer 14 1st UV curable resin 15 2nd UV curable resin 20 Slot rod 21 Groove 22 Groove bottom

Claims (4)

[Claims] 1. A method of aligning a plurality of optical fiber core wires and UV
In an optical fiber ribbon coated with a curable resin, both sides of the optical fiber ribbon coated with the first and second UV-curable resins having different Young's moduli are separated by a plane formed by aligning the optical fibers. An optical fiber ribbon. 2. The method according to claim 2, wherein the first UV-curable resin has a Young's modulus of 80 to 90 (kg / mm ² , 23 ° C.).
Has a Young's modulus of 110 to 130 (kg /
(mm ² , 23 ° C.). 3. The optical fiber ribbon according to claim 1, wherein one of the first and second UV-curable resins is colored. 4. The optical fiber ribbon according to claim 1, wherein a side of the optical fiber tape coated with a UV-curable resin having a higher Young's modulus is opposed to a bottom surface of a groove of a slot rod. An optical fiber cable, wherein a predetermined number of the optical fiber cables are stacked and housed in the groove.